我试图根据这个答案将LKM中的结构发送到用户区：Netlink Sockets in C using the 3.X linux kernel

答案本身的代码是完全可编译的,但是当我尝试发送结构而不是char *时,我会在userland中获得段错误.

这是我改变的：

netlinkKernel.c

我加：

typedef struct test{
    int a;
    char *b;
} s_test;

并替换

char *msg = "Hello from kernel";

---

msg_size = strlen(msg);

---

strncpy(nlmsg_data(nlh),msg,msg_size);

同

s_test x;
x.a = 42;
x.b = "The answer";

---

msg_size(sizeof(x));

---

memcpy(nlmsg_data(nlh),&x,msg_size);

netlinkUser.c

我添加相同的结构和替换

printf("Received message payload: %s\n",(char *)NLMSG_DATA(nlh));

同

s_test *x = (s_test *)NLMSG_DATA(nlh);
printf("Received message payload: %d - %s\n",x->a,x->b);

问题出在哪儿？